Beaglebone-Black HDMI audio

The added ti,gpio-clock is a basic clock that can be enabled and disabled trough a gpio output. The DT binding document for the clock is also added. For EPROBE_DEFER handling the registering of the clock has to be delayed until of_clk_get() call time.

Signed-off-by Jyri Sarha <[email protected]>

---
 .../devicetree/bindings/clock/ti/gpio-clock.txt    |   21 ++
 drivers/clk/ti/Makefile                            |    2 +-
 drivers/clk/ti/gpio.c                              |  202 ++++++++++++++++++++
 3 files changed, 224 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/clock/ti/gpio-clock.txt
 create mode 100644 drivers/clk/ti/gpio.c

Documentation/devicetree/bindings/clock/ti/gpio-clock.txt new file +21 -0

new file mode 100644
index 0000000..2eb854d
@@ -0,0 +1,21 @@
+Binding for simple gpio controlled clock.
+
+This binding uses the common clock binding[1].
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Required properties:
+- compatible : shall be "ti,gpio-clock".
+- #clock-cells : from common clock binding; shall be set to 0.
+- enable-gpios : GPIO reference for enabling and disabling the clock.
+
+Optional properties:
+- clocks: Maximum of one parent clock is supported.
+
+Example:
+	clock {
+		compatible = "ti,gpio-clock";
+		clocks = <&parentclk>;
+		#clock-cells = <0>;
+		enable-gpios = <&gpio 1 GPIO_ACTIVE_HIGH>;
+	};

drivers/clk/ti/Makefile +1 -1

index ed4d0aa..88074d3 100644
@@ -1,7 +1,7 @@
 ifneq ($(CONFIG_OF),)
 obj-y					+= clk.o autoidle.o clockdomain.o
 clk-common				= dpll.o composite.o divider.o gate.o \
-					  fixed-factor.o mux.o apll.o
+					  fixed-factor.o mux.o apll.o gpio.o
 obj-$(CONFIG_SOC_AM33XX)		+= $(clk-common) clk-33xx.o
 obj-$(CONFIG_ARCH_OMAP2)		+= $(clk-common) interface.o clk-2xxx.o
 obj-$(CONFIG_ARCH_OMAP3)		+= $(clk-common) interface.o clk-3xxx.o

drivers/clk/ti/gpio.c new file +202 -0

new file mode 100644
index 0000000..f4c668e
@@ -0,0 +1,202 @@
+/*
+ * Copyright (C) 2012 - 2014 Texas Instruments Incorporated - http://www.ti.com
+ * Author: Jyri Sarha <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Gpio controlled clock implementation
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+#include <linux/err.h>
+#include <linux/device.h>
+
+struct clk_gpio {
+	struct clk_hw	hw;
+	struct gpio_desc *gpiod;
+};
+
+/**
+ * DOC: basic gpio controlled clock which can be enabled and disabled
+ *      with gpio output
+ * Traits of this clock:
+ * prepare - clk_(un)prepare only ensures parent is (un)prepared
+ * enable - clk_enable and clk_disable are functional & control gpio
+ * rate - inherits rate from parent.  No clk_set_rate support
+ * parent - fixed parent.  No clk_set_parent support
+ */
+
+#define to_clk_gpio(_hw) container_of(_hw, struct clk_gpio, hw)
+
+static int clk_gpio_enable(struct clk_hw *hw)
+{
+	struct clk_gpio *clk = to_clk_gpio(hw);
+
+	gpiod_set_value(clk->gpiod, 1);
+
+	return 0;
+}
+
+static void clk_gpio_disable(struct clk_hw *hw)
+{
+	struct clk_gpio *clk = to_clk_gpio(hw);
+
+	gpiod_set_value(clk->gpiod, 0);
+}
+
+static int clk_gpio_is_enabled(struct clk_hw *hw)
+{
+	struct clk_gpio *clk = to_clk_gpio(hw);
+
+	return gpiod_get_value(clk->gpiod);
+}
+
+static const struct clk_ops clk_gpio_ops = {
+	.enable = clk_gpio_enable,
+	.disable = clk_gpio_disable,
+	.is_enabled = clk_gpio_is_enabled,
+};
+
+/**
+ * clk_register_gpio - register a gpip clock with the clock framework
+ * @dev: device that is registering this clock
+ * @name: name of this clock
+ * @parent_name: name of this clock's parent
+ * @gpiod: gpio descriptor to control this clock
+ */
+static struct clk *clk_register_gpio(struct device *dev, const char *name,
+		const char *parent_name, struct gpio_desc *gpiod,
+		unsigned long flags)
+{
+	struct clk_gpio *clk_gpio = NULL;
+	struct clk *clk = ERR_PTR(-EINVAL);
+	struct clk_init_data init = { NULL };
+	unsigned long gpio_flags;
+	int err;
+
+	if (gpiod_is_active_low(gpiod))
+		gpio_flags = GPIOF_OUT_INIT_HIGH;
+	else
+		gpio_flags = GPIOF_OUT_INIT_LOW;
+
+	if (dev)
+		err = devm_gpio_request_one(dev, desc_to_gpio(gpiod),
+					    gpio_flags, name);
+	else
+		err = gpio_request_one(desc_to_gpio(gpiod), gpio_flags, name);
+
+	if (err) {
+		pr_err("%s: %s: Error requesting clock control gpio %u\n",
+		       __func__, name, desc_to_gpio(gpiod));
+		return ERR_PTR(err);
+	}
+
+	if (dev)
+		clk_gpio = devm_kzalloc(dev, sizeof(struct clk_gpio),
+					GFP_KERNEL);
+	else
+		clk_gpio = kzalloc(sizeof(struct clk_gpio), GFP_KERNEL);
+
+	if (!clk_gpio)
+		goto clk_register_gpio_err;
+
+	init.name = name;
+	init.ops = &clk_gpio_ops;
+	init.flags = flags | CLK_IS_BASIC;
+	init.parent_names = (parent_name ? &parent_name : NULL);
+	init.num_parents = (parent_name ? 1 : 0);
+
+	clk_gpio->gpiod = gpiod;
+	clk_gpio->hw.init = &init;
+
+	clk = clk_register(dev, &clk_gpio->hw);
+
+	if (!IS_ERR(clk))
+		return clk;
+
+	if (!dev)
+		kfree(clk_gpio);
+
+clk_register_gpio_err:
+	gpiod_put(gpiod);
+
+	return clk;
+}
+
+/**
+ * The clk_register_gpio has to be delayed, because the EPROBE_DEFER
+ * can not be handled properly at of_clk_init() call time.
+ */
+
+struct clk_gpio_delayed_register_data {
+	struct device_node *node;
+	struct mutex lock;
+	struct clk *clk;
+};
+
+static
+struct clk *of_clk_gpio_delayed_register_get(struct of_phandle_args *clkspec,
+					     void *_data)
+{
+	struct clk_gpio_delayed_register_data *data = _data;
+	struct clk *clk;
+	const char *clk_name = data->node->name;
+	const char *parent_name;
+	struct gpio_desc *gpiod;
+	int gpio;
+
+	mutex_lock(&data->lock);
+
+	if (data->clk) {
+		mutex_unlock(&data->lock);
+		return data->clk;
+	}
+
+	gpio = of_get_named_gpio_flags(data->node, "enable-gpios", 0, NULL);
+	if (gpio < 0) {
+		mutex_unlock(&data->lock);
+		if (gpio != -EPROBE_DEFER)
+			pr_err("%s: %s: Can't get 'enable-gpios' DT property\n",
+			       __func__, clk_name);
+		return ERR_PTR(gpio);
+	}
+	gpiod = gpio_to_desc(gpio);
+
+	parent_name = of_clk_get_parent_name(data->node, 0);
+
+	clk = clk_register_gpio(NULL, clk_name, parent_name, gpiod, 0);
+	if (IS_ERR(clk)) {
+		mutex_unlock(&data->lock);
+		return clk;
+	}
+
+	data->clk = clk;
+	mutex_unlock(&data->lock);
+
+	return clk;
+}
+
+/**
+ * of_gpio_clk_setup() - Setup function for gpio controlled clock
+ */
+static void __init of_gpio_clk_setup(struct device_node *node)
+{
+	struct clk_gpio_delayed_register_data *data;
+
+	data = kzalloc(sizeof(struct clk_gpio_delayed_register_data),
+		       GFP_KERNEL);
+	if (!data)
+		return;
+
+	data->node = node;
+	mutex_init(&data->lock);
+
+	of_clk_add_provider(node, of_clk_gpio_delayed_register_get, data);
+}
+CLK_OF_DECLARE(gpio_clk, "ti,gpio-clock", of_gpio_clk_setup);

Signature · 6 lines

1.7.9.5

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Quoted 4 lines · Jyri Sarha

The added ti,gpio-clock is a basic clock that can be enabled and disabled trough a gpio output. The DT binding document for the clock is also added. For EPROBE_DEFER handling the registering of the clock has to be delayed until of_clk_get() call time.

I guess this is basically an AND gate with the GPIO and parent clock as inputs? Or is this something more complex that we might want to do more things with later?

If it's the former it sounds like this could be a completely generic "gpio-gate-clock".

Quoted 10 lines · Mark Rutland

Quoted 4 lines · Jyri Sarha

The added ti,gpio-clock is a basic clock that can be enabled and disabled trough a gpio output. The DT binding document for the clock is also added. For EPROBE_DEFER handling the registering of the clock has to be delayed until of_clk_get() call time.

I guess this is basically an AND gate with the GPIO and parent clock as inputs? Or is this something more complex that we might want to do more things with later?

Quoted 3 lines

If it's the former it sounds like this could be a completely generic "gpio-gate-clock".

Yes, its completely generic. However, since there has been no response to my several earlier attempts to get this patch in I finally gave up and moved it under clk/ti.

"gpio-gate-clock" sound like more accurate name for ti. I'll change that.

Do you think I should give this one more try to get it in as generic basic clock?

Add machine driver support for BeagleBone-Black HDMI audio. BBB has NXP TDA998X HDMI transmitter connected to McASP port in I2S mode. The 44100 Hz sample-rate and it's multiples can not be accurately produced on BBB. The only supported sample format is SNDRV_PCM_FORMAT_S32_LE. The 8 least significant bits are ignored.

Signed-off-by Jyri Sarha <[email protected]>

---
 .../bindings/sound/davinci-evm-audio.txt           |    4 +-
 sound/soc/davinci/davinci-evm.c                    |   82 +++++++++++++++++++-
 2 files changed, 83 insertions(+), 3 deletions(-)

Documentation/devicetree/bindings/sound/davinci-evm-audio.txt +0 -0

index 963e100..c137436 100644

Quoted 17 lines · Jyri Sarha

Add machine driver support for BeagleBone-Black HDMI audio. BBB has NXP TDA998X HDMI transmitter connected to McASP port in I2S mode. The 44100 Hz sample-rate and it's multiples can not be accurately produced on BBB. The only supported sample format is SNDRV_PCM_FORMAT_S32_LE. The 8 least significant bits are ignored.

Signed-off-by Jyri Sarha <[email protected]>

---
  .../bindings/sound/davinci-evm-audio.txt           |    4 +-
  sound/soc/davinci/davinci-evm.c                    |   82 +++++++++++++++++++-
  2 files changed, 83 insertions(+), 3 deletions(-)

Documentation/devicetree/bindings/sound/davinci-evm-audio.txt +0 -0

index 963e100..c137436 100644

Documentation/devicetree/bindings/sound/davinci-evm-audio.txt line 6

Quoted 7 lines

Documentation/devicetree/bindings/sound/davinci-evm-audio.txt +3 -1

@@ -1,7 +1,9 @@
  * Texas Instruments SoC audio setups with TLV320AIC3X Codec
 
  Required properties:
-- compatible : "ti,da830-evm-audio" : forDM365/DA8xx/OMAPL1x/AM33xx
+- compatible : "ti,da830-evm-audio" : for DM365/DA8xx/OMAPL1x/AM33xx
+               "ti,am335x-beaglebone-black-audio" : for Beaglebone-black HDMI
+                                                    audio

To keep this legible I'd recommend reorganising this like:

- compatible: should contain one of:
* "ti,da830-evm-audio" for DM365/DA8xx/OMAPL1x/AM33xx
* "ti,am335x-beaglebone-black-audio" for Beaglebone-black HDMI audio

For the BBB case, do you expect both strings or just the BBB-specific string?

Is the 'x' in the BBB string a wildcard? If we know the particular number for BBB we should use that.

Quoted 28 lines · Mark Rutland

Quoted 17 lines · Jyri Sarha

Add machine driver support for BeagleBone-Black HDMI audio. BBB has NXP TDA998X HDMI transmitter connected to McASP port in I2S mode. The 44100 Hz sample-rate and it's multiples can not be accurately produced on BBB. The only supported sample format is SNDRV_PCM_FORMAT_S32_LE. The 8 least significant bits are ignored.

Signed-off-by Jyri Sarha <[email protected]>

---
  .../bindings/sound/davinci-evm-audio.txt           |    4 +-
  sound/soc/davinci/davinci-evm.c                    |   82 +++++++++++++++++++-
  2 files changed, 83 insertions(+), 3 deletions(-)

Documentation/devicetree/bindings/sound/davinci-evm-audio.txt +0 -0

index 963e100..c137436 100644

Documentation/devicetree/bindings/sound/davinci-evm-audio.txt line 6

Quoted 7 lines

Documentation/devicetree/bindings/sound/davinci-evm-audio.txt +3 -1

@@ -1,7 +1,9 @@
  * Texas Instruments SoC audio setups with TLV320AIC3X Codec
 
  Required properties:
-- compatible : "ti,da830-evm-audio" : forDM365/DA8xx/OMAPL1x/AM33xx
+- compatible : "ti,da830-evm-audio" : for DM365/DA8xx/OMAPL1x/AM33xx
+               "ti,am335x-beaglebone-black-audio" : for Beaglebone-black HDMI
+                                                    audio

To keep this legible I'd recommend reorganising this like:

Quoted 4 lines

- compatible: should contain one of:
* "ti,da830-evm-audio" for DM365/DA8xx/OMAPL1x/AM33xx
* "ti,am335x-beaglebone-black-audio" for Beaglebone-black HDMI audio

The above looks indeed better. I'll make the change. Oh, and I probably should change the first line to something like:

* TI SoC audio using McASP to connect to TLV320AIC3X or HDMI endcoder

Quoted 3 lines

For the BBB case, do you expect both strings or just the BBB-specific string?

Normally just the one. In theory a BBB with an audio-cape on top could utilize another sound node with "ti,da830-evm-audio" compatible property.

Quoted 3 lines

Is the 'x' in the BBB string a wildcard? If we know the particular number for BBB we should use that.

Yes, its a wild card. BBBs have been made at least with AM3358 and AM3359 SoCs.

Sorry, I meant in the same node. I take it we never expect:

compatible = "ti,am335x-beaglebone-black-audio", "ti,da830-evm-audio";

Quoted 6 lines

Quoted 6 lines

Quoted 3 lines

Quoted 3 lines

Is the 'x' in the BBB string a wildcard? If we know the particular number for BBB we should use that.

Yes, its a wild card. BBBs have been made at least with AM3358 and AM3359 SoCs.

In general we've pushed back against wildcard strings, and used the first implementation for the naming. We should be able to use "ti,am3358-beaglebone-black-audio" for AM335{8,9} assuming the block is the same? Otherwise we might need separate strings anyway.

Could we drop the SoC id completely and make it just "beaglebone-black-audio"?

The board design is the unique factor here, not the SoC. McASP block can be found from several TI SoCs.

Add external clock provider for am33xx devices.

Signed-off-by Jyri Sarha <[email protected]>

---
 arch/arm/boot/dts/am33xx.dtsi |   10 ++++++++++
 1 file changed, 10 insertions(+)

arch/arm/boot/dts/am33xx.dtsi +10 -0

index 3a0a161..d2cc397 100644
@@ -92,6 +92,16 @@
 		pinctrl-single,function-mask = <0x7f>;
 	};
 
+	ext_clocks {
+		compatible = "ti,external-clocks";
+
+		ext_clocks: clocks {
+		};
+
+		ext_clockdomains: clockdomains {
+		};
+	};
+
 	/*
 	 * XXX: Use a flat representation of the AM33XX interconnect.
 	 * The real AM33XX interconnect network is quite complex. Since

Signature · 1 line

1.7.9.5

Quoted 1 line · Jyri Sarha

Add external clock provider for am33xx devices.

Please send all the .dts and defconfig changes separately so I can pick them up and we don't get pointless merge conflicts.

Regards,

TOny

Quoted 13 lines

Signed-off-by Jyri Sarha <[email protected]>

---
  arch/arm/boot/dts/am33xx.dtsi |   10 ++++++++++
  1 file changed, 10 insertions(+)

arch/arm/boot/dts/am33xx.dtsi +0 -0

index 3a0a161..d2cc397 100644
@@ -92,6 +92,16 @@
  		pinctrl-single,function-mask = <0x7f>;
  	};
 

Quoted 14 lines

arch/arm/boot/dts/am33xx.dtsi +10 -1

+	ext_clocks {
+		compatible = "ti,external-clocks";
+
+		ext_clocks: clocks {
+		};
+
+		ext_clockdomains: clockdomains {
+		};
+	};
+
  	/*
  	 * XXX: Use a flat representation of the AM33XX interconnect.
  	 * The real AM33XX interconnect network is quite complex. Since
--

Quoted 2 lines

1.7.9.5